|
Fundus changes in central retinal artery occlusion.Retina.
2007 Mar;27(3):276-89.
PURPOSE: To
investigate systematically the ophthalmoscopic fundus findings
associated with central retinal artery occlusion (CRAO). METHODS: The
study included 240 consecutive patients (248 eyes) with CRAO. The eyes
underwent detailed fundus evaluation and stereoscopic color fundus
photography at initial and follow-up visits. Patients without evidence
of giant cell arteritis were advised to have carotid Doppler imaging
and echocardiography to determine the source of emboli. CRAO was
classified into 3 types: permanent CRAO (175 eyes), permanent CRAO
with cilioretinal artery sparing (35 eyes), and transient CRAO (38
eyes). In the three types of CRAO, acute-phase and late-phase changes
in the retina, optic disk, and retinal vessels were evaluated.
RESULTS: The main findings during the initial examination in our
clinic for permanent CRAO were retinal opacity in the posterior pole
(58%), cherry-red spot (90%), box-carring (19%), retinal arterial
attenuation (32%), and optic disk edema (22%) and pallor (39%). The
most frequent findings identified at the late stage, based on
survivorship curves, were optic atrophy (91%), retinal arterial
attenuation (58%), cilioretinal collaterals (18%), and macular retinal
pigment epithelial changes (11%). Compared with permanent CRAO,
permanent CRAO with cilioretinal artery sparing was associated with a
lower incidence of all macular and optic disk abnormalities. For
transient CRAO, the incidence of initial findings varied greatly
compared with the other types. Intraarterial emboli were observed in
20% of patients. Carotid Doppler evaluation identified carotid
vascular plaques in 67% of patients tested and hemodynamically
significant (>50%) obstruction in 32%. Four percent of CRAOs presented
with simultaneous bilateral onset. CONCLUSIONS: The type and incidence
of fundus findings at the initial visit and in the late phase of CRAO
vary by its type. This study confirms that retinal opacity is
predominantly evident in the posterior retina, that optic disk
findings at presentation are common, that CRAO associated with
normal-appearing retinal vessels and/or optic disk is not rare, and
that observation of emboli is infrequent. Clinicians should be aware
of the various presentation findings during the acute and late stages
of CRAO and its various types. A complete picture of CRAO is provided
by combined information of our clinical and experimental studies of
CRAO.
Central retinal artery occlusion: findings
in optical coherence tomography and functional correlations.
Eur J Med Res. 2006 Jun 30;11(6):250-2.
BACKGROUND:
Visual prognosis in central retinal artery occlusion (CRAO) is poor
and not predictable in individual patients. There may be a correlation
between visual acuity and extent of initial macular edema. METHODS:
Central retinal thickness of eleven patients with subtotal CRAO was
measured with optical coherence tomography (OCT). Patients'
acute-stage macular thicknesses were compared to those of later
stages. Values are given as mean (+/-standard error; range). RESULTS:
The mean age of the eleven patients was 68.8 years (62-75). Eight men
and three women were examined. The mean initial duration of CRAO was
24.7 (+/- 5.0; 4-77) hours. Initial central thickness was 372.5 (+/-
27.1; 258-522) microm. After 5.7 (+/- 1.5; 1-17) months, mean
reduction in macular edema was 197 (+/- 31.3; 63-391) microm. Visual
acuity (VA) improved from 0.0125 (+/- 0.2; blindness -0.6) to 0.035
(+/- 0.2; blindness - 0.8) namely 4.5 lines. This difference was
significant (p= 0.023). 6/11 patients (55 %) initially had a
pronounced central retinal edema (>380 microm). No correlation was
found between the initial macular edema height and visual improvement.
CONCLUSIONS: The extent of macular edema differs widely and does not
affect visual prognosis in CRAO eyes.
Central retinal artery occlusion: visual outcome.
Am J Ophthalmol. 2005 Sep;140(3):376-91.
PURPOSE: To
investigate systematically the natural history of visual outcome in
central retinal artery occlusion (CRAO). DESIGN: Cohort study.
METHODS: At entry, 244 consecutive patients (260 eyes) with CRAO (seen
consecutively from 1973 to 2000) had a detailed ocular and medical
history and ocular evaluation. CRAO eyes were classified into four
categories: non-arteritic (NA) CRAO (171 eyes), NA-CRAO with
cilioretinal artery sparing (35), transient NA-CRAO (41), and
arteritic CRAO (13). RESULTS: Within 7 days of onset of CRAO, initial
visual acuity differed among the four CRAO types (P < .0001). In eyes
with vision of counting fingers or worse, it improved in 82% of eyes
with transient NA-CRAO, 67% of eyes with NA-CRAO with cilioretinal
artery sparing, and 22% of eyes with NA-CRAO. Visual acuity improved
primarily within the first 7 days (P < .0001). In the central
30-degree visual field, central scotoma was most common. Central
visual field improved in 39% with transient NA-CRAO, 25% with NA-CRAO
with cilioretinal artery sparing, and 21% with NA-CRAO. Peripheral
visual field was normal in 62.9% of eyes with transient NA-CRAO and
22.1% in those with NA-CRAO. In 51.9% of eyes with NA-CRAO, the only
remaining visual field was a peripheral island. Peripheral fields
improved in NA-CRAO (39%) and in transient NA-CRAO (39%). CONCLUSIONS:
Classification of CRAO is crucial for understanding differences in
visual outcome. Marked improvement in visual acuity and visual field
can occur without treatment and is determined by several factors.
Visual field information is essential to evaluate visual disability in
CRAO.
Central retinal artery occlusion. Retinal survival time.
Exp Eye Res. 2004 Mar;78(3):723-36.
PURPOSE: To
investigate the retinal survival time following central retinal artery
occlusion (CRAO). METHODS: In 38 elderly, atherosclerotic and
hypertensive rhesus monkeys, transient CRAO (varying from 97 to 240
min) was produced by temporarily clamping the CRA at its site of entry
into the optic nerve. Stereoscopic color fundus photography,
fluorescein fundus angiography, electroretinography (ERG), and visual
evoked potential (VEP) recording were performed before and during CRA
clamping, after unclamping, and serially thereafter. After unclamping
of the CRA, the animals were followed for variable lengths of time
(median duration 8.14 weeks). Finally, the eyes and optic nerves were
examined histologically. The data on ERG changes were analyzed in the
following four time frames: (1) baseline before CRA clamping, (2)
during CRA clamping, (3) immediately after unclamping, and (4) at the
end of follow-up. Duration of CRAO was divided into four groups: 97,
105-120, 150-165, and > or = 180 min. RESULTS: A 'negative ERG'
appeared during CRA clamping. With removal of the CRA clamp, there was
b-wave recovery, with differential rates of recovery of ERG-eyes with
shorter CRAO recovered sooner than those with longer occlusion. On
removal of clamp, recovery was seen in scotopic 24 dB b-wave, photopic
0 dB single flash b-wave and 30 Hz flicker, with the b/a ratio of the
combined rod and cone response and selective rod response showing
statistically significant differences amongst the shorter and longer
periods of CRAO. A delayed normalization of the depressed b/a ratio
immediately after CRA reperfusion may indicate high-grade ischemic
damage. At the final follow-up test session, no clear-cut derangement
of any ERG parameter was seen for any group, with subtotal b-wave
amplitude recovery for all groups. Longer CRAO produced incomplete VEP
recovery. On histology, in the macular retina, eyes with CRAO for 97
min showed practically no damage, but duration of CRAO was found to be
significantly associated with the amount of damage in the ganglion
cell layer (p = 0.009) and inner nuclear layer (p = 0.017). Outer
nuclear and plexiform layers and photoreceptors showed no damage at
all with CRAO. There was no significant association of the ERG
measures and histologic changes with any of the residual retinal
circulation variables. CONCLUSIONS: Our electrophysiologic,
histopathologic and morphometric studies showed that the retina of
old, atherosclerotic, hypertensive rhesus monkeys suffers no
detectable damage with CRAO of 97 min but above that level, the longer
the CRAO, the more extensive the irreversible damage. The study
suggests that CRAO lasting for about 240 min results in massive
irreversible retinal damage.
|
